Portable cofferdam



FIG. 1 is a left perspective view of a portable cofferdam showing ournew design;

FIG. 2 is a right view of the portable cofferdam of FIG. 1; and,

FIG. 3 is a top view of the portable cofferdam of FIG. 1.

The broken line portions of the drawings are included to show unclaimedsubject matter and form no part of the claimed design.

CLAIM The ornamental design for a portable cofferdam, as shown anddescribed.